Patio stain damage (cypress)

[lowlandtrees]

The neighbour of a customer has alleged that cypress trees that we were pruning have stained a few slabs on his new ornate patio. He has tried to power wash them without success. Any ideas how to remove these stains? I think that patio cleaner will discolour the slabs and if he has tried to power wash them it is unlikely that detergent will remove it? The guy is looking for a relay of his patio!

[chopperpete]

I had an issue with some oak slabs I left on my concrete drive...used brick acid and jet wash, not 100% successful!

Edited September 29, 2020 by chopperpete

[eggsarascal]

Depends what the surface is, if it's Indian sandstone or similar don't use patio cleaner that you see in the diy sheds it will have hydrochloric acid in it, you will end up with a bigger mess than you started with. I've been to plenty that customers have tried to clean themselves and said, sorry fella you knackered it.

[lowlandtrees]

5 hours ago, eggsarascal said:

Depends what the surface is, if it's Indian sandstone or similar don't use patio cleaner that you see in the diy sheds it will have hydrochloric acid in it, you will end up with a bigger mess than you started with. I've been to plenty that customers have tried to clean themselves and said, sorry fella you knackered it.

 

[lowlandtrees]

It’s one of these expensive riven slabs. 

[eggsarascal]

17 minutes ago, lowlandtrees said:

 

That picture isn't the best but it looks like natural grey riven slabs 450x450, if there aren't too many knock them out and replace them. About £15-20 m2.

[The avantgardener]

36 minutes ago, eggsarascal said:

That picture isn't the best but it looks like natural grey riven slabs 450x450, if there aren't too many knock them out and replace them. About £15-20 m2.

You will never colour match the mortar exactly if you replace them, and this guy seems a royal pita and wouldn’t be happy with it anyway.

 I would first ask what patio cleaner he has used and see if the blame can be put back on him.
The staining looks more like bird shit than conifer cuttings.

[eggsarascal]

4 minutes ago, The avantgardener said:

You will never colour match the mortar exactly if you replace them, and this guy seems a royal pita and wouldn’t be happy with it anyway.

 I would first ask what patio cleaner he has used and see if the blame can be put back on him.
The staining looks more like bird shit than conifer cuttings.

You are correct you wouldn't match the mortar exactly, if it was bird crap a decent pressure washer would have it away no problem. If I HAD to make a call I'd say the marks are rust stains from something being sat on them, if they are he's stuck with them.

[Paddy1000111]

If it is sap then I would suggest anything that removes sap. IPA alcohol and a small but hard car detailing brush might work, or using any sort of vehicle tar/sap remover. Even white spirit removes sap. If you're talking about replacing it then try anything. Even bleach might work as a last ditch before digging it up. Nothing to loose except 2-3 quid on some cleaner 

[Dan Maynard]

I don't get how the trees can have stained the patio in the first place, have you formally acknowledged that you have caused the damage yet? This sounds a bit like the famous sawdust causing car to need a respray, in which case you say you'll need to refer to your insurers and they will most likely tell him to go away, politely.